U.S. patent application number 10/567722 was filed with the patent office on 2007-02-01 for styrenic thermoplastics composition.
This patent application is currently assigned to LG CHEM. LTD.. Invention is credited to Sung-tae Ahn, Sung-je Cha, Yun-kyoung Cho, Dong-chul Kim, Chan-hong Lee.
Application Number | 20070027256 10/567722 |
Document ID | / |
Family ID | 36748275 |
Filed Date | 2007-02-01 |
United States Patent
Application |
20070027256 |
Kind Code |
A1 |
Kim; Dong-chul ; et
al. |
February 1, 2007 |
Styrenic thermoplastics composition
Abstract
The present invention relates to an acrylic rubber-modified
copolymer and the styrenic thermoplastics composition using the
same. More particularly, the present invention relates to the
styrenic thermoplastics composition having superior appearance and
thermoformability, which is obtained by adding 0.5-20 parts by
weight of an acrylic rubber-modified copolymer having a rubber
particle size ranging from 800 to 6, 000 .ANG.to 100 parts by
weight of a resin of 10-50 parts by weight of a graft copolymer
comprising rubber-modified styrene and 30-70 parts by weight of a
copolymer comprising styrene.
Inventors: |
Kim; Dong-chul; (Daejeon,
KR) ; Lee; Chan-hong; (Daejeon, KR) ; Cha;
Sung-je; (Seoul, KR) ; Cho; Yun-kyoung;
(Daejeon, KR) ; Ahn; Sung-tae; (Daejeon,
KR) |
Correspondence
Address: |
CANTOR COLBURN, LLP
55 GRIFFIN ROAD SOUTH
BLOOMFIELD
CT
06002
US
|
Assignee: |
LG CHEM. LTD.
Seoul
KR
|
Family ID: |
36748275 |
Appl. No.: |
10/567722 |
Filed: |
October 8, 2004 |
PCT Filed: |
October 8, 2004 |
PCT NO: |
PCT/KR04/02572 |
371 Date: |
February 8, 2006 |
Current U.S.
Class: |
525/70 |
Current CPC
Class: |
C08L 25/06 20130101;
C08L 2666/02 20130101; C08L 51/04 20130101; C08L 51/04
20130101 |
Class at
Publication: |
525/070 |
International
Class: |
C08L 51/00 20060101
C08L051/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 8, 2003 |
KR |
10-2003-0069927 |
Claims
1. A styrenic thermoplastics composition comprising: 100 parts by
weight of a resin comprising 10-50 parts by weight of a graft
copolymer comprising rubber-modified styrene and 30-70 parts by
weight of a copolymer comprising styrene; 0.5-20 parts by weight of
an acrylic rubber-modified copolymer having a rubber particle size
ranging from 800 to 6,000 .ANG.; 5-15 parts by weight of a seed
polymerized from an alkyl acrylate; 45-75 parts by weight of a core
polymerized from an alkyl acrylate; and 10-50 parts by weight of a
shell polymerized from an alkyl methacrylate and/or an alkyl
acrylate.
2. The styrenic thermoplastics composition of claim 1, wherein the
graft copolymer comprising rubber-modified styrene comprises: 30-65
parts by weight of at least one selected from the group consisting
of styrene, .alpha.-methylstyrene, p-methylstyrene, vinyltoluene
and t-butylstyrene; 10-30 parts by weight of at least one selected
from the group consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile; and 10-60 parts by weight of a rubber.
3. The styrenic thermoplastics composition of claim 2, wherein the
rubber is polybutadiene, styrene-butadiene copolymer, polyisoprene
or butadieneisoprene copolymer having a particle size ranging from
500 to 4,000 .ANG..
4. The styrenic thermoplastics composition of claim 1, wherein the
copolymer comprising styrene comprises: 50-90 parts by weight of at
least one selected from the group consisting of styrene,
.alpha.-methylstyrene, p-methylstyrene, vinyltoluene and
t-butylstyrene; and 10-50 parts by weight of at least one selected
from the group consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile.
5. The styrenic thermoplastics composition of claim 1, wherein the
copolymer comprising styrene has a weight-average molecular weight
ranging from 50,000 to 200,000.
6. An extrusion sheet manufactured from the styrenic thermoplastics
composition of claim 1.
7. An acrylic rubber-modified copolymer having a rubber particle
size ranging from 800 to 6.000 .ANG., comprising: 5-15 parts by
weight of a seed polymerized from an alkyl acrylate; 45-75 parts by
weight of a core polymerized from an alkyl acrylate; and 10-50
parts by weight of a shell polymerized from an alkyl methacrylate
and/or an alkyl acrylate.
8. The acrylic rubber-modified copolymer of claim 7, wherein the
seed comprises 95.0-99.95 wt % of an alkyl acrylate having 2-8
carbon atoms in the alkyl group.
9. The acrylic rubber-modified copolymer of claim 7, wherein the
core comprises 95.0-99.95 wt % of an alkyl acrylate having 2-8
carbon atoms in the alkyl group.
10. The acrylic rubber-modified copolymer of claim 7, wherein the
shell comprises: 90-100 wt % of an alkyl methacrylate having 1-4
carbon atoms in the alkyl group; and 0-10 wt % of an alkyl acrylate
having 1-4 carbon atoms in the alkyl group.
11. The acrylic rubber-modified copolymer of claim 8, wherein the
alkyl acrylate is at least one selected from the group consisting
of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl
acrylate, butyl acrylate, hexyl acrylate, octyl acrylate,
2-ethylhexyl acrylate, homopolymers thereof and copolymers
thereof.
12. The acrylic rubber-modified copolymer of claim 10, wherein the
alkyl methacrylate having 1-4 carbon atoms in the alkyl group is at
least one selected from the group consisting of methyl
methacrylate, ethyl methacrylate, propyl methacrylate, isopropyl
methacrylate and butyl methacrylate.
13. The acrylic rubber-modified copolymer of claim 10, wherein the
alkyl acrylate having 1-4 carbon atoms in the alkyl group is at
least one selected from the group consisting of ethyl acrylate,
methyl acrylate and butyl acrylate.
14. (canceled)
15. The acrylic rubber-modified copolymer of claim 9, wherein the
alkyl acrylate is at least one selected from the group consisting
of methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl
acrylate, butyl acrylate, hexyl acrylate, octyl acrylate,
2-ethylhexyl acrylate, homopolymers thereof and copolymers thereof.
Description
TECHNICAL FIELD
[0001] The present invention relates to an acrylic rubber-modified
copolymer and a styrenic thermoplastics composition using the same.
More particularly, the present invention relates to a styrenic
thermoplastics composition using an acrylic rubber-modified
copolymer which has superior appearance and thermoformability and
is obtained by adding an acrylic rubber-modified copolymer having a
rubber particle size ranging from 800 to 6,000 .ANG. to a mixture
resin of a graft copolymer comprising rubber-modified styrene and a
copolymer comprising styrene.
BACKGROUND ART
[0002] A rubber-modified styrene resin (referred as an ABS resin)
has good impact resistance, toughness, rigidity, chemical
resistance, molding processability and luster, etc. Therefore, it
is widely used as an extrusion-molding resin for manufacturing OA
equipments, household electric appliances, daily commodities, etc.
As electronic appliances, particularly refrigerators, are becoming
larger and lighter, the rubber-modified styrene resin is
sheet-extruded then vacuum-molded and used as an inner cabinet of a
refrigerator.
[0003] An inner cabinet of a refrigerator is manufactured by
extruding a resin sheet and thermoforming the resin sheet to obtain
a wanted shape. Therefore, the resin requires good extrusion
stability and thermoformability. Also, because it is used in the
inner cabinet or door cabinet of a refrigerator, it should also
have good appearance characteristics such as luster.
[0004] In order to improve thermoformability of a resin, Korea
Patent Publication No. 2002-0050475 discloses a method of adding a
graft polymer prepared from graft polymerization of a mixture of a
vinyl cyanide compound and an aromatic vinyl compound to an acrylic
synthetic rubber (referred to as an `ASA resin`). However, it has
unsatisfactory appearance characteristics such as poor luster.
DISCLOSURE
[0005] In view of these problems, it is an object of the present
invention to provide a styrenic thermoplastics composition having
superior appearance and thermoformability by adding an acrylic
rubber-modified copolymer having a rubber particle size ranging
from 800 to 6,000 .ANG., to a resin comprising a graft copolymer
comprising rubber-modified styrene and a copolymer comprising
styrene.
[0006] It is another object of the present invention to provide an
extrusion sheet manufactured from the styrenic thermoplastics
composition.
[0007] It is also another object of the present invention to
provide an acrylic rubber-modified copolymer capable of improving
thermoformability and luster of a resin by polymerizing alkyl
acrylate as a seed and a core, with alkyl methacrylate and/or alkyl
acrylate as a shell, so that the rubber particle size ranges from
800 to 6,000 .ANG..
[0008] The above and other objects of the present invention can be
accomplished by embodiments of the present invention as will be
described hereinafter.
[0009] According to an aspect of the present invention, there is
provided a styrenic thermoplastics composition comprising 100 parts
by weight of a resin comprising 10-50 parts by weight of a graft
copolymer comprising rubber-modified styrene and 30-70 parts by
weight of a copolymer comprising styrene; and 0.5-20 parts by
weight of an acrylic rubber-modified copolymer having a rubber
particle size ranging from 800 to 6,000 .ANG..
[0010] The graft copolymer comprising rubber-modified styrene may
comprise 30-65 parts by weight of at least one selected from the
group consisting of styrene, .alpha.--methylstyrene,
p-methylstyrene, vinyltoluene and t-butylstyrene; 10-30 parts by
weight of at least one selected from the group consisting of
acrylonitrile, methacrylonitrile and ethacrylonitrile; and 10-60
parts by weight of a rubber.
[0011] The rubber has a particle size ranging from 500 to 4,000
.ANG.and may be polybutdiene, styrene-butadiene copolymer,
polyisoprene or butadiene-isoprene copolymer.
[0012] The copolymer comprising styrene may comprise 50-90 parts by
weight of at least one selected from the group consisting of
styrene, .alpha.-methylstyrene, p-methylstyrene, vinyltoluene and
t-butylstyrene; and 10-50 parts by weight of at least one selected
from the group consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile.
[0013] The copolymer comprising styrene may have a weight-average
molecular weight ranging from 50,000 to 200,000.
[0014] The present invention also provides an extrusion sheet
manufactured from the styrenic thermoplastics composition.
[0015] The present invention also provides an acrylic
rubber-modified copolymer comprising 5-15 parts by weight of a seed
polymerized from an alkyl acrylate; 45-75 parts by weight of a core
polymerized from an alkyl acrylate; and 10-50 parts by weight of a
shell polymerized from an alkyl methacrylate and/or an alkyl
acrylate.
[0016] The seed may comprise 95.0-9995 wt % of an alkyl acrylate
having 2-8 carbon atoms in the alkyl group.
[0017] The core may comprise 95.0-9995 wt % of an alkyl acrylate
having 2-8 carbon atoms in the alkyl group.
[0018] The shell may comprise 90-100 wt % of an alkyl methacrylate
having 1-4 alrbon atoms in the alkyl group; and 0-10 wt % of an
alkyl acrylate having 1-4 carbon atoms in the alkyl group.
[0019] The alkyl acrylate having 2-8 carbon atoms in the alkyl
group may be at least one selected from the group consisting of
methyl acrylate, ethyl acrylate, propyl acrylate, isopropyl
acrylate, butyl acrylate, hexyl acrylate, octyl acrylate,
2-ethylhexyl acrylate, homopolymers thereof and copolymers
thereof.
[0020] The alkyl methacrylate having 1-4 carbon atoms in the alkyl
group may be at least one selected from the group consisting of
methyl methacrylate, ethyl methacrylate, propyl methacrylate,
isopropyl methacrylate and butyl methacrylate.
[0021] The alkyl acrylate having 1-4 carbon atoms in the alkyl
group may be at least one selected from the group consisting of
ethyl acrylate, methyl acrylate and butyl acrylate.
[0022] The acrylic rubber-modified copolymer may have a rubber
particle size ranging from 800 to 6,000 .ANG..
[0023] Hereinafter, the present invention is described in more
detail.
[0024] The present invention provides a styrenic thermoplastics
composition comprising 100 parts by weight of a resin comprising
10-50 parts by weight of a graft copolymer comprising
rubber-modified styrene and 30-70 parts by weight of a copolymer
comprising styrene; and 0.5-20 parts by weight of an acrylic
rubber-modified copolymer having a rubber particle size ranging
from 800 to 6,000 .ANG..
[0025] Preferably, the present invention provides a styrenic
thermoplastics composition comprising a graft copolymer comprising
rubber-modified styrene and a copolymer comprising styrene; and
2-13 parts by weight of an acrylic rubber-modified copolymer having
a rubber particle size ranging from 3000 to 5,000 .ANG..
[0026] The graft copolymer comprising rubber-modified styrene is a
copolymer prepared by grafting a compound comprising 30-65 parts by
weight of at least one selected from the group consisting of
styrene, a -methylstyrene, p-methylstyrene, vinyltoluene and
t-butylstyrene; and 10-30 parts by weight of at least one selected
from the group consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile to 10-60 parts by weight of a rubber.
[0027] The rubber may be polybutdiene, styrene-butadiene copolymer,
polyisoprene, or butadiene-isoprene copolymer, etc. It has a rubber
particle size ranging from 500 to 4,000 .ANG..
[0028] Although a graft copolymer comprising rubber-modified
styrene may be polymerized by the conventional method, it is
preferably synthesized by bulk polymerization or emulsion
polymerization. The graft copolymer comprising rubber-modified
styrene may have a weight-average molecular weight ranging from
50,000 to 150,000.
[0029] Preferably, the graft copolymer comprising rubber-modified
styrene is an acrylonitrile/butadiene/styrene (ABS) resin obtained
by grafting acrylonitrile and styrene to a butadiene rubber.
[0030] The copolymer comprising rubber-modified styrene is
comprised in 10-50 parts by weight per the total weight of the
styrene thermoplastic resin.
[0031] The copolymer comprising styrene comprises 50-90 parts by
weight of at least one selected from the group consisting of
styrene, .alpha.-methylstyrene, p-methylstyrene, vinyltoluene and
t-butylstyrene; and 10-50 parts by weight of at least one selected
from the group consisting of acrylonitrile, methacrylonitrile and
ethacrylonitrile.
[0032] Although the copolymer comprising styrene may be polymerized
by the conventional method, it is preferably synthesized by bulk
polymerization or emulsion polymerization. The copolymer comprising
styrene may have a weight-average molecular weight ranging from
50,000 to 200,000. The copolymer comprising styrene is comprised in
30-70 parts by weight per the total weight of the styrene
thermoplastic resin, depending on the content of the graft
copolymer comprising rubber-modified styrene.
[0033] The acrylic rubber-modified copolymer having a rubber
particle size ranging from 800 to 6,000 .ANG., is comprised in
0.5-20 parts by weight, preferably in 2-13 parts by weight, per 100
parts by weight of a resin comprising a graft copolymer comprising
rubber-modified styrene and a copolymer comprising styrene. If its
content is below 0.5 parts by weight, thermoformability worsen and
if it exceeds 20 parts by weight, appearance characteristics such
as luster may worsen.
[0034] The styrenic thermoplastics composition of the present
invention may be prepared by the conventional blending method.
[0035] The styrenic thermoplastics composition of the present
invention may further comprise at least one additive selected from
the group consisting of a lubricant, a heat stabilizer, an
antioxidant, an optical stabilizer, an anti-dropping agent, a
pigment, an inorganic filler.
[0036] The present invention also provides an acrylic
rubber-modified copolymer comprising 5-15 parts by weight of a seed
polymerized from alkyl acrylate; 45-75 parts by weight of a core
polymerized from alkyl acrylate; and 10-50 parts by weight of a
shell polymerized from alkyl methacrylate and/or alkyl
acrylate.
[0037] That is, the acrylic rubber-modified copolymer is prepared
by polymerizing a seed, growing rubber particles by adding a
monomer that constitutes a core and adding a monomer that
constitutes a shell, so that the shell surrounds the core surface.
Resultantly, a latex having a particle size ranging from 800 to
6,000 .ANG.is obtained.
[0038] The seed and the core rubber layers comprise 50-90 parts by
weight of a rubber monomer and the shell layer comprises 10-50
parts by weight of an alkyl methacrylate and/or an alkyl acrylate
monomer(s).
[0039] The acrylic rubber-modified copolymer is described in more
detail.
[0040] Preferably, the acrylic rubber-modified copolymer comprises
5-15 parts by weight of the seed and the seed comprises 95.0-9995
wt % of an alkyl acrylate having 2-8 carbon atoms in the alkyl
group. It may further comprise a crosslinking agent.
[0041] Also, preferably, the acrylic rubber-modified copolymer
comprises 45-75 parts by weight of the core rubber layer and the
core rubber layer comprises 95.0-9995 wt % of an alkyl acrylate
having 2-8 carbon atoms in the alkyl group. It m further comprise a
crosslinking agent.
[0042] In the seed and the core, the alkyl acrylate having 2-8
carbon atoms in the alkyl group may be at least one selected from
the group consisting of methyl acryl, ethyl acrylate, propyl
acrylate, isopropyl acrylate, butyl acrylate, hexyl acrylate, octyl
acrylate, 2-ethylhexyl acrylate, homopolymers thereof and
copolymers thereof.
[0043] The crosslinking agent may be Et least one monomer selected
from the group consisting of 1,3-butanediol diacrylate,
1,3-bulanediol dimethacrylate, 1,4-butanediol diacrylate,
1,4-butanediol dimethacrylate, allyl acrylate, allyl methacrylate,
trimethylolpropane triacrylate, tetraethylene glycol diacrylate,
tetraethylene glycol dimethacrylate and divinylbenzene. Preferably,
the crosslinking agent is comprised in 0.05-5.0 wt % per the total
weight of monomers in latex.
[0044] The acrylic rubber-modified copolymer comprises 10-50 parts
by weight of a shell. A monomer constituting the shell comprises an
alkyl methacrylate and/or an alkyl acrylate monomer.
[0045] The shell is polymerized from 90-100 wt % of Et least one
alkyl methacrylate having 1-4 carbon atoms in the alkyl group
selected from the group consisting of methyl methacrylate, ethyl
methacrylate, propyl methacrylate, isopropyl methacrylate and butyl
methacrylate and 0-10 wt % of at least one alkyl acrylate having
1-4 carbon atoms in the alkyl group selected from the group
consisting of ethyl acrylate, methyl acrylate and butyl
acrylate.
[0046] The acrylic rubber-modified copolymer has a rubber particle
size ranging from 800 to 6,000 .ANG., preferably from 3,000 to
5,000 .ANG.. If the rubber particle size is below 800 .ANG.,
thermoformability may worsen and if it exceeds 6,000 .ANG.,
appearance characteristics such as luster, etc may worsen.
[0047] The acrylic rubber-modified copolymer may further comprise
an emulsifier and a polymerization initiator.
[0048] The emulsifier may be at least one ionic emulsifier selected
from the group consisting of a saturated or unsaturated potassium
salt of fatty acid, potassium salt of oleic acid, sodium lauryl
sulfate and sodium dodecylbenzenesulfonate. Preferably, it is
comprised in 0.1-4.0 wt % per the total weight of polymerization
monomers.
[0049] The polymerization initiator may be at least one selected
from the group consisting of ammonium persulfate, potassium
persulfate, benzoyl peroxide, azobisbutyronitrile, butyl
hydroperoxide and cumine hydroperoxide. Among these, the one that
initiates polymerization by pyrolysis or oxidation/reduction is
preferable.
[0050] The acrylic rubber-modified copolymer may be obtained by
coagulating the latex of the acrylic rubber-modified copolymer with
an electrolyte, an organic acid or an inorganic acid, filtering and
drying it. The electrolyte nay be calcium chloride or a
water-soluble magnesium salt such as magnesium sulfite.
[0051] Hereinafter, the present invention is described more
specifically by examples but the present invention is not limited
to or by them.
BEST MODE
[0052] <Preparing step 1-1: Preparation of Graft Copolymer
Comprising Rubber-Modified Styrene>
[0053] A graft copolymer comprising rubber-modified styrene of LG
Chem was acrylonitrile/butadiene/styrene (ABS) obtained by grafting
15 parts by weight of acrylonitrile and 35 parts by weight of
styrene to 50 parts by weight a butadiene rubber, by emulsion
polymerization.
[0054] <Preparing step 1-2: Preparation of Copolymer Comprising
Styrene>
[0055] A copolymer comprising styrene comprising 70 parts by weight
of styrene and 30 parts by weight of acrylonitrile was synthesized
by bulk polymerization.
[0056] <Preparing step 1-3: Preparation of Acrylic
Rubber-Modified Copolymer having rubber particle size ranging from
800 to 6,000 .ANG.>
[0057] 1) Reaction Step 1: Polymerization of Seed
[0058] 385.13 g of ion exchange water was put in a reactor. The
temperature inside the reactor was raised to 70.degree. C. When the
temperature of the ion exchange water reached 70.degree. C., 30.81
g of butyl acrylate, 0.05 g of allyl methacrylate, 0.10 g of
1,3-butanediol dimethacrylate and 16.59 g of a potassium sat
solution of unsaturated fatty acid (8 wt % solution) were added at
the same time. 8.9 g of potassium persulfate (3 wt %) was added
while maintaining the internal temperature of the reactor at
70.degree. C. to polymerize a seed.
[0059] 2) Reaction Step 2: Polymerization of Core Rubber Layer
[0060] 924.42 g of ion exchange water, 462.2 g of butyl acrylate,
0.450 g of allyl methacrylate, 0.90 g of 1,3-butanediol
dimethacrylate and 74.68 g of an unsaturated fatty acid solution (8
wt % solution) were mixed to prepare a pre-emulsion. After a stable
pre-emulsion was obtained, it was continuously added to the seed
latex prepared in Reaction step 1 at a constant flow rate for 2
hours. At the sane time, 2.5 g of butyl hydroperoxide (10 wt %) was
also added continuously for 2 hours, so that polymerization took
place. Then, aging was performed at 70.degree. C. for 1 hour to
obtain a core.
[0061] 3) Reaction Step 3: Polymerization of Shell
[0062] 60 g of ion exchange water, 123.25 g of methyl methacrylate
and 13.8 g of a potassium sat solution of unsaturated fatty acid (8
wt % solution) were mixed to prepare a pre-emulsion. The
pre-emulsion and 23.1 g of a potassium persulfate solution (3 wt %
solution) were divided in two and added to the latex prepared in
Reaction step 2 with an interval of 30 minutes, thereby performing
polymerization of a shell. Aging was performed for 1 hour while
marinating the internal temperature of the reactor at 70.degree. C.
Particle size of the resultant latex was measured with an HPL
(Nicomp 370 HPL) by dynamic laser light scattering. The particle
size was 4,500 .ANG..
[0063] 4) Reaction Step 4: Coagulation of Acrylic Rubber-Modified
Copolymer
[0064] 2 wt % of a sulfuric acid aqueous solution (5 wt % solution)
was added to the resultant latex at the sane time to coagulate it.
The coagulated mixture was heated to 90.degree. C. After 10 minutes
of aging, the mixture was cooled down. The mixture was washed with
ion exchange water for 2-3 times to remove byproducts and filtered
to obtain a coagulated acrylic rubber-modified copolymer. It was
dried at 85.degree. C. for 2 hours using an FBD(fluidized bed
dryer) to obtain a powdery acrylic rubber-modified copolymer.
EXAMPLE 1
[0065] 2 parts by weight of an acrylic rubber-modified copolymer
was mixed with 100 parts by weight of a resin comprising 30 parts
by weight of a graft copolymer comprising rubber-modified styrene
and 70 parts by weight of a copolymer comprising styrene to prepare
the styrenic thermoplastics composition.
EXAMPLE 2
[0066] A styrenic thermoplastic resin composition was prepared in
the same manner as in Example 1 except that 4 parts by weight,
instead of 2 parts by weight, of the acrylic rubber-modified
copolymer was used.
EXAMPLE 3
[0067] The styrenic thermoplastics composition was prepared in the
sane manner as in Example 1 except that 6 parts by weight, instead
of 2 parts by weight, of the acrylic rubber-modified copolymer was
used.
EXAMPLE 4
[0068] The styrenic thermoplastics composition was prepared in the
sane manner as in Example 1 except that 12 parts by weight, instead
of 2 parts by weight, of the acrylic rubber-modified copolymer was
used.
COMPARATIVE EXAMPLE 1
[0069] The styrenic thermoplastics composition was prepared in the
sane manner as in Example 1 except that the acrylic rubber-modified
copolymer was not used.
COMPARATIVE EXAMPLE 2
[0070] The styrenic thermoplastics composition was prepared in the
sane manner as in Example 1 except that 30 parts by weight, instead
of 2 parts by weight, of the acrylic rubber-modified copolymer was
used.
EXPERIMENTAL EXAMPLE
[0071] Physical properties of the compositions prepared in Examples
1-4 and Comparative Examples 1-2, were measured in accordance with
following methods.
[0072] Tensile strength was measured according to ASTM D638, luster
was measured according to ASTM D2985 and the melt index was
measured according to ASTM D1238.
[0073] Tensile strength EL high temperature was measured with
INSTRON Model No. 4301. Measurement sample was prepared by
extruding each pellet measuring 100 mm.times.100 mm.times.3.2 mm
and cutting the sample to a length of 51 mm, an area of 15 mm.sup.2
and a measurement area of 6.5 mm.sup.2. The prepared sample was
maintained Et 150.degree. C. for 15 minutes before measurement.
Tensile strength at high temperature was measured at rate of 200
mm/min. The higher the tensile strength, the better the
thermoformability.
[0074] Physical property measurement results for Examples 1-4 and
Comparative Examples 1-2 are presented in Table 1 below.
TABLE-US-00001 TABLE 1 Tensile Tensile strength strength Fluidity
Luster at high temperature (Kgf/cm.sup.2) (g/10 min) (%)
(Kgf/cm.sup.2) Example 1 503 4.5 80 4.1 Example 2 510 4.8 82 4.4
Example 3 506 4.5 83 4.6 Example 4 512 4.5 86 5.1 Comparative 500
4.0 76 3.7 Example 1 Comparative 518 3.0 70 4.5 Example 2
[0075] As shown in Table 1, the styrenic thermoplastics of the
present invention has better appearance characteristics than those
of Comparative Examples 1 and 2, which is confirmed by better
luster. Also, the styrenic thermoplastics of the present invention
has better thermoformability than those of Comparative Examples 1
and 2, which is confirmed by higher tensile strength a high
temperature.
INDUSTRIAL APPLICABILITY
[0076] As apparent from the above description, the acrylic
rubber-modified copolymer of the present invention and the styrenic
thermoplastics composition using the sane, which is prepared by
adding an acrylic rubber-modified copolymer having a rubber
particle size ranging from 800 to 6,000 .ANG. to a resin comprising
a graft copolymer comprising rubber-modified styrene and a
copolymer comprising styrene, is applicable to extrusion sheets and
improves appearance and thermoformability.
[0077] While the present invention has been described in detail
with reference to exemplary embodiments, it will be understood by
those skilled in the art that various substitutions and
modifications can be made thereto without departing from the spirit
and scope of the present invention as defined by the following
claims.
* * * * *